This invention relates to an animal ear tag.
It is well known to provide an animal ear tag having a coupling arrangement which incorporates a headed stem which is forced through an animal""s ear and through an opening in a female part of the tag which is located at the side of the ear opposite to that through which the headed stem is forced. A secure coupling of the tag to the animal""s ear is required to ensure that the ear tag remains in place in the animal""s ear. Therefore, the coupling should be of a type which resists decoupling, especially when the tag becomes snagged in an obstruction such as a fence, gate, etc. Also, it is desirable to provide an ear tag construction which is such as to resist the tag being removed and reused for illicit retagging of animals. The ear tag, therefore, needs as far as possible to be tamperproof.
Over the years, various attempts have been made to render an ear tag tamperproof. To this end, there has been previously proposed an ear tag construction of a type described and claimed in New Zealand patent specification 213378 in which a collar is located within an enclosed boss which surrounds the opening in the female part of the tag. When the tag is installed in the ear of an animal, the headed stem is forced through the opening and locates within the collar inside the enclosed boss. Good retention characteristics are exhibited by the tag. Furthermore, access to the head is rendered difficult if an effort is made to cause the head to be forced back out through the female opening to achieve decoupling of the tag and thereby permit the tag or one or both of the components to be illicitly reused.
It was also proposed that the retention characteristics be such that applying a retraction or pulling force to the stem of the tag (when endeavouring to pull the tag apart) the head would separate from the stem and remain in the collar. This would thereby render the tag/tag components non-reusable.
The tag described in New Zealand patent specification No 213378 largely achieved its objectives. However, the object of the present invention is to provide an animal ear tag which has improved tamperproof characteristics.
Broadly, according to one aspect of the present invention, there is provided an animal tamperproof ear tag including a female opening through which a head of a stem of a coupling member can pass to effect a coupling action when installing the tag on an animal, the female opening being formed as part of a separate enclosed boss of rigid hard moulded material with a thick wall section, the having a flange extending peripherally from an external surface thereof, said flange being moulded into the resilient material forming a part of the ear tag so as to anchor said boss to the tag part, wherein the female opening is of decreasing cross-sectional area from an external part of the boss as it extends into the cavity, said female opening being at least part formed by a plurality of projections which extend inwardly from the exterior of the boss and form at the distal ends thereof a retention surface which, in use, engages with the head of the stem of said coupling member and wherein the boss component has an internal cavity in which the head can reside after passing through the female opening, the internal cavity being in close conformity with the head of the stem.
Preferably the boss is made of two separate sections, a top section which has a peripheral flange and an open end which provides a shoulder, an a base section which includes a peripheral flange and incorporates the projection in female opening, a peripheral wall of the base section engaging in said open end in a snug fit with the end of the peripheral wall butted up to said shoulder, the peripheral flanges being mated face to face.
In the preferred form of the invention the material is a resilient material and the boss includes anchoring means for anchoring the boss component with said resilient material. The anchoring means can be formed by a plurality of openings in the flanges.
The hard material can be a fibre reinforced plastics material.